Haibike bosch2014 chain on front cog issue

[Sp00k]

I made over 2k km on a single chain and finally changed it to a new one same 11s Sram.
I've made sure to fit it to same length of 108 links as previous one.
After some tests today I have some serious issue of chain catching on a cog as shown on photo.
Happens under heavier pedaling load.
Had this happen on previous chain for me just once.
Any suggestions how to fix that?

 

[flecc]

The small front sprocket probably has enough wear for the teeth to be hooked. They could then trap and carry the shorter new chain links around the sprocket, the hook not being able to let go at the feed off point.

A new sprocket with the new chain should cure it.
.

 

[Emo Rider]

I had the same issue with the drive sprocket of my BH. I took it off, turned it around and reassembled. Problem solved for another couple of thousand miles and then I will have to replace it. Perhaps the same could be done with your front drive gear.

 

[RobF]

Not the first report of chain suck on the small Bosch front ring.

I wonder if suck is more likely because of the smaller ring.

The chain must be following a tighter radius than it would on a more conventional set up.

 

[SRS]

I think the smallness does contribute, especially if mud is around.

Someone said a while ago, small sprockets work fine on motorbikes.
They do but motorbikes do not have derailleur gears that by their very design allows chain suck to happen.

I'd have to ask the question, whats the benefit to the user?

I have taken a look at the Yamaha system. This allows for standard, off the shelf rings and two of them at that. Seems to make much more sense to me.

 

[Sp00k]

Right, planned to change front cog anyway. Ordered a 15 teeth one. Anybody tried it compared to 16 default one? Wanted to get even lower gear when doing some long climbs.
Otherwise I find that small front cog rather stupid. I'll definitely go next with Yamaha that gives flexibility of changing the front cog to your needs.

 

[Croxden]

I've not yet had any problems, advantage of the Rohloff hub I suppose.

 

[Sp00k]

Is there a standard key to remove that front sprocket? I have the key for the crank arm but read that need some spider key for the sprocket. Found just original Bosch's one on ebay at some unreasonable price.

 

[Martin@e-bikeshop]

Is there a standard key to remove that front sprocket? I have the key for the crank arm but read that need some spider key for the sprocket. Found just original Bosch's one on ebay at some unreasonable price.

The tool is here.
When replacing any drivetrain its best practice to replace all the components, as you can see the new chain is now hooking on the old sprocket. Contact your place of purchase for any support / spares you may require.

Martin

 

[Sp00k]

Well this isn't completely true. I'd run the rear cassette till it dies. In this case of a new chain the front sprocket is obviously to be replaced. Wasn't just sure that my issue was caused by the wear not by the improper chain tension.
Though if rear cassette is still running why to throw it away?
More than that all the components run great with my old chain I just decided to replace it to get more life out of the rear cassette which is x10 times more expensive than chain.

My place of purchase proposed me a front sprocket for 60euros when original from ebay is 20 at max ) Same for rear cassette proposed 300 euros when I can get one from ebay for 180.
This was an offer direclty from Haibike sevice at special wholesale prices

Oh 30 pounds for the spider key. Thanks )

 

[Sp00k]

Begin to feel sorry for Bosch. To make a cheap crap plastic nut and develop am exclusive 30 pounds key for it I'm around 85% sure I'll go with Yamaha on next bike.
More than that key for 2012 motors doesn't work for 2014. ROFL.

 

[Sp00k]

This was indeed caused by front sprocket wear.
got 15T one from ebay connex one at rather low cost.
As for the key it is not really needed. That plastic nut can be unscrewed easily for free
I really like 15T sprocket with 10-42 cassette. Have lower highest speed around 45km/h now but lowest gears are now way better for climbing.